Use N saline by default until BSL <15  0.45% saline + 5% dex
Diabetic Ketoacidosis
Definition
Epidemiology
Pathophysiology
Investigations
Management
Incr BSL / AG >10 / Bic <15 / pH <7.3 / mod ketonaemia
Fetal mortality 30-50%
Type I > type II; 20-30% in newly diagnosed DM; incidence 0.5% of DM; most common <18yrs;
RF for DKA in known DM: poor metabolic control; low SE status; prev DKA; adolescent female; psych disorder
RF for DKA in unknown DM: <5yrs, FH DM, low SE status, meds (eg. High dose steroids, antipsychotics, immunosuppressants)
Trigger: Concurrent infection, non-compliance with meds, MI
Absolute insulin deficiency
Decr glu uptake by cells
Incr counter-regulatory hormones – glucagon, adrenaline, GH, cortisol
Incr gluconeogenesis, incr glycogenolysis
Incr lipolysis  f.a.  overproduction of ACoA  ketogenesis
Acetoacetate: acetoacetate:betaHB = >6:1; measured by Ketostix urine test (>3); urinary ketones may increase with trt as beta-HB
converted to acetoacetate
Beta hydroxybutyrate: converted peripherally to acetoacetate; prevalent in alcoholic ketoacidosis; not detected on normal testing so ketones may be
negative initially in alcoholic KA; detected on Medisense blood test (>3)
Acetone: from decarboxylation of acetoacetate  excreted by kidneys and lungs; detected on Acetest (>5); responsible for ketotic breath
Amino acids, Lactate
 Incr glu  glycosuria, osmotic diuresis  loss of H20, Na, K, Mg, PO4  hypoV and lactic acidosis
BSL may not be incr if: liver failure, alcoholic; due to impaired gluconeogenesis
Check BSL hourly; continuous cardiac monitoring; accurate fluid balance; hourly neuro obs; U+E Q2-4hrly; Ca, Mg, Phos, FBC (incr WBC, L shift indicated
lactic acidosis), lactate; Blood culture, sputum culture: if sepsis suspected; Amylase will be factitiously increased, use lipase; Urine: ketones (positive in
>95%); culture; CT head: if altered LOC
VBG: AGMA; may get met alk from vomiting with incr AG as only clue of DKA; if HCO3 lower than expected for AG, concomitant NAGMA (seen in patients
who are still well hydrated)
ETCO2: can be used in children; <29mmHg = 80% sens
average body fluid deficit 5-10L (ie. 100ml/kg, 10% dehydration);
Na
correct for glu: Na + ((Glu – 5.5) / 3)
average Na deficit 5-10mmol/kg
K
correct for pH: decr pH 0.1 = incr K 0.5
average K deficit 3-5mmol/kg
Osmolality
osm:
(2 x Na) + Glu + Ur
increased
Aim decr BSL by no more than 5/hr, decr osm by 1-2/hr; endpoint: ketones cleared, normal AG
Mild = pH >7.3, tolerating PO fluids, <5% dehydrated  can consider treating with SC insulin only and not down DKA route
Mod-severe: Nurse head up, NBM, NGT (if ileus), consider heparin, treat underlying cause
IVF: start within 30mins ED arrival; aim to replace total deficit over 48hrs to avoid cerebral oedema; caution in children, elderly, CCF, CRF; use N saline
initially
Adults:
1L stat (if dehydrated ++)
Children:
Adults:
10-20ml/kg bolus N saline
 1L over 1hr
if shocked, until haemodynamically stable
 1L over 2hrs  1L over 4hrs  1L over 10hrs use N saline
Add K to fluids in 2nd hour and once UO established and K <5
Children:  replace deficit over
48hrs
If K >5 = none
K 4-5 = 10mmol/hr
K 3-4 = 30mmol/hr
K <3 = 40mmol/hr
Na <150 / osm <320  use N saline
Na >150 / osm >320  use 0.45% saline and correct over 72hrs
Deficit = %dehydration X weight X 10 (remember to subtract any bolus given
Both:
)
 When BSL <15 / if BSL decreasing by >5/hr  use 0.45% saline + 5% dex, aiming BSL 12-15
If BSL <10 but ongoing ketones
 use 0.45% saline + 10% dex
 Once K <5.5, patient PU’ing, insulin infusion started, add 40mmol
KCl per 1L bag
Insulin: start 1hr after initial fluids; only start if K >3.4, otherwise replace K first
0.1 iu/kg/hr (max 6iu/hr) actrapid  decr to 0.05 iu/kg/hr when BSL <12 and acidosis improving, aiming BSL 9-14; if
BSL still too low despite this, can stop infusion for 10-15mins only
Use 0.05iu/kg/hr if new onset DM in child or young child, as will be sensitive to insulin
Decr to 0.05iu/kg/hr for 4hrs if K <3
Criteria for change to SC: BSL <11, HCO3 >16-18, pH >7.3, AG <15, E+D, normal LOC, ketones cleared
When stopping, give mixed short and long acting SC dose @ least 1hr before stopping infusion
Phosphate / Mg: only if severe / symptomatic decr phos / Mg
K2PO4 5mmol/hr
MgSO4 2.5g over 1hr
HCO3: only if pH <7, HCO3 <5, life-threatening hyperK, coma, and haemodynamic compromise unresponsive to fluid resus
May cause rapid decr K, worsened intracellular acidosis, impaired offloading of O2, Na overload, hypertonicity, cerebral oedema (4x incr risk), vol
overload, paradoxical CNS acidosis
HCO3 mmol = 0.15 x base deficit x kg
/
0.5-2mmol/kg over 1-2hrs
Endpoint: pH >7.1, HCO3 >10
Discharge
Prognosis
Admit ICU if: In children: <2yrs, pH <7.1, altered LOC, need for arterial line, severe hyperosmolar dehydration
Patient education (incr insulin by 4iu or more when intercurrent illness, even if not eating)
Mortality 5-15% (0.3-1% in children) - due to underlying disease, cerebral oedema, thromboembolism
Poor prognostic factors: ARF, altered LOC, hypotension
Complications
Cerebral
oedema
DD
Other crises
Decr BSL, decr K, decr phos, ARDS, recurrence, thrombosis
Leading cause of mortality from DKA; 70% mortality; 10% survivors have permanent neuro sequelae; more common in children (1% incidence)
Risk factors: 1st presentation; long history poor control; <5yrs; initial corrected Na >160; severe incr osm; persistent hypoNa; severe acidosis; ??related to
overaggressive fluid resus
Sx: onset 4-12hrs after starting trt; headache, decr Na, altered LOC, decr HR, HTN, decr RR, incontinence, pupil changes, seizures, papilloedema
Trt: 0.5-1g/kg mannitol IV bolus / 5-10ml/kg 3% saline IV over 30mins; give half maintenance fluids; admit PICU; neurosurg review; CT;
hyperventilate if ETT
DD: cerebral venous sinus thrombosis (may require contrast CT / MRI for detection if initial CT normal)
Ethylene glycol, isopropyl alcohol, salicylates
New onset hyperG but no DKA: give 0.1iu/kg SC regular insulin; admit
HyperG, known DM, no DKA: give additional 10% of normal daily insulin dose as regular insulin SC
Notes from: Dunn, Cameron (adult and child), TinTin, Starship Guidelines